1. Field of the Invention
The invention describes an apparatus for positioning a plurality of spaced-apart power semiconductor modules and a method for surface treatment of the positioned power semiconductor modules.
2. Description of the Related Art
The point of departure for the invention is, for example, a plurality of power semiconductor modules manufactured in accordance with DE 196 30 173 A1, which are disposed spaced apart from one another in a shipping package as described by DE 10 358 834 A1. Before being shipped, it is preferred that a heat-conducting layer be applied to the substrates of the power semiconductor modules, so that, after shipping, the power semiconductor modules can be disposed in an arrangement such as a current inverter immediately, without further surface treatment.
The aforementioned power semiconductor modules have two main faces, the first main face being formed by a substrate, and the second having electrical contact elements disposed therein. The first main face faces the interior of the power semiconductor module, and carries the power semiconductor components. The second main face, disposed on the side opposite to the interior of the power semiconductor module, connects the module thermally conductively to a cooling component (heat sink). This thermally conductive connection between the substrate and the cooling component is formed in the prior art by an intermediate layer comprising a heat-conducting layer of a so-called heat-conducting paste.
To assure efficient heat transfer after the power semiconductor module is mounted on the heat sink, this heat-conducting paste must be embodied as a homogeneous layer or as a homogeneous distribution of individual layer elements. Such layers of heat-conducting paste, however, have the disadvantage, being a pastelike layer, of being vulnerable to damage in terms of their homogeneity. For this reason, in the prior art, the heat-conducting paste is preferably applied immediately before the power semiconductor module is mounted on the heat sink. Since this layer, though, must have the highest possible homogeneity (or in other words a uniform layer thickness), screenprinting processes are for instance suitable for the purpose, but are not necessarily readily available at the assembly site.
Shipping packages for the aforementioned power semiconductor module are disclosed in DE 103 58 834 A1. Such shipping packages arrange a plurality of power semiconductor modules at a spacing from one another that is defined to a tolerance of only a few millimeters. Moreover, these packages are embodied such that the two main faces of each power semiconductor module do not come into contact with the shipping package, or come into contact with only a slight but defined portion thereof.